The problem with most hybrids is that you cannot tow anything with it which makes them useless for most sailors.

Diesels are very popular in Europe, especially for those that drive more than 30k/KMs a year.
My Renault stationwagon uses about 5,5L for every 100KMs and 10L when towing a cat.

The amount of road tax you pay is determined by a so called Energy Label which is used to stimulate both producers and consumers to drive cars with smaller CO2 footprints:
http://en.wikipedia.org/wiki/European_Union_energy_label#Cars